Added Jason dependency

[joaobalsini]

An error is triggered when following the example on the Readme.

Interactive Elixir (1.8.2) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> {:ok, id} = EsCqrsMaestro.Counter.new()
{:ok, %HLClock.Timestamp{counter: 0, node_id: 88558817, time: 1562859371627}}

iex(2)> EsCqrsMaestro.Counter.evaluate(%Maestro.Types.Command{aggregate_id: id, type: "increment_counter", data: %{}})

12:37:36.641 [debug] QUERY OK source="snapshots" db=2.4ms
SELECT s0."aggregate_id", s0."sequence", s0."body" FROM "snapshots" AS s0 WHERE (s0."sequence" > $1) AND (s0."sequence" <= $2) AND (s0."aggregate_id" = $3) [0, 2147483647, <<1, 107, 225, 173, 124, 107, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>]
 
12:37:36.643 [debug] QUERY OK source="event_log" db=2.6ms
SELECT e0."timestamp", e0."aggregate_id", e0."sequence", e0."type", e0."body" FROM "event_log" AS e0 WHERE (e0."sequence" > $1) AND (e0."sequence" <= $2) AND (e0."aggregate_id" = $3) ORDER BY e0."timestamp" [0, 2147483647, <<1, 107, 225, 173, 124, 107, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>]
 
12:37:36.675 [debug] QUERY OK db=0.2ms
begin []
 
12:37:36.692 [debug] QUERY ERROR db=5.6ms
INSERT INTO "event_log" ("aggregate_id","body","sequence","timestamp","type") VALUES ($1,$2,$3,$4,$5) [<<1, 107, 225, 173, 124, 107, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>, %{}, 1, <<1, 107, 225, 174, 200, 133, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>, "counter_incremented"]
 
12:37:36.692 [debug] QUERY OK db=0.2ms
rollback []
{:error,
 %UndefinedFunctionError{
   arity: 1,
   function: :encode_to_iodata!,
   message: nil,
   module: Jason,
   reason: nil
 },
 [
   {Jason, :encode_to_iodata!, [%{}], []},
   {Postgrex.DefaultTypes, :encode_params, 3,
    [file: 'lib/postgrex/type_module.ex', line: 721]},
   {DBConnection.Query.Postgrex.Query, :encode, 3,
    [file: 'lib/postgrex/query.ex', line: 62]},
   {DBConnection, :encode, 5, [file: 'lib/db_connection.ex', line: 1148]},
   {DBConnection, :run_prepare_execute, 5,
    [file: 'lib/db_connection.ex', line: 1246]},
   {DBConnection, :parsed_prepare_execute, 5,
    [file: 'lib/db_connection.ex', line: 540]},
   {DBConnection, :prepare_execute, 4,
    [file: 'lib/db_connection.ex', line: 533]},
   {Postgrex, :query, 4, [file: 'lib/postgrex.ex', line: 196]}
 ]}

Some of Maestro dependencies (like ecto) has Jason as optional dependency, it might have changed recently and broke Maestro.

As soon as we add Jason as an dependency to our project the problem is solved:

Interactive Elixir (1.8.2) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> {:ok, id} = EsCqrsMaestro.Counter.new()
{:ok, %HLClock.Timestamp{counter: 0, node_id: 88558817, time: 1562860067026}}

iex(2)> EsCqrsMaestro.Counter.evaluate(%Maestro.Types.Command{aggregate_id: id, type: "increment_counter", data: %{}})

12:47:57.360 [debug] QUERY OK source="snapshots" db=2.0ms
SELECT s0."aggregate_id", s0."sequence", s0."body" FROM "snapshots" AS s0 WHERE (s0."sequence" > $1) AND (s0."sequence" <= $2) AND (s0."aggregate_id" = $3) [0, 2147483647, <<1, 107, 225, 184, 24, 210, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>]
 
12:47:57.364 [debug] QUERY OK source="event_log" db=2.9ms queue=0.1ms
SELECT e0."timestamp", e0."aggregate_id", e0."sequence", e0."type", e0."body" FROM "event_log" AS e0 WHERE (e0."sequence" > $1) AND (e0."sequence" <= $2) AND (e0."aggregate_id" = $3) ORDER BY e0."timestamp" [0, 2147483647, <<1, 107, 225, 184, 24, 210, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>]
 
12:47:57.397 [debug] QUERY OK db=16.4ms queue=0.1ms
begin []
 
12:47:57.400 [debug] QUERY OK db=1.1ms
INSERT INTO "event_log" ("aggregate_id","body","sequence","timestamp","type") VALUES ($1,$2,$3,$4,$5) [<<1, 107, 225, 184, 24, 210, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>, %{}, 1, <<1, 107, 225, 184, 65, 52, 0, 0, 0, 0, 0, 0, 5, 71, 76, 225>>, "counter_incremented"]
 
12:47:57.410 [debug] QUERY OK db=9.5ms
commit []
:ok

[coveralls]

Pull Request Test Coverage Report for Build 68

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 97.452%

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Totals
Change from base Build 67:	0.0%
Covered Lines:	153
Relevant Lines:	157

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💛 - Coveralls

[NeilMenne]

Excellent find. Thanks! It's definitely an optional dependency I have been explicitly adding which has masked this problem.